Article carrier for overhead conveyor



Aug. 28, 1962 J. c. WALSH ETAL 3,051,096

ARTICLE CARRIER FOR OVERHEAD CONVEYOR FIG.

I l I I JOHN C. WALSH WILLIAM M. HAZEL ro/v KENNETH P. JUHL INVENTORS e.72"....

EDWARD 7? H01. LAND J2.

Aug. 28, 1962 Filed April 25, 1960 J. C. WALSH ETAL ARTICLE CARRIER FOROVERHEAD CONVEYOR 2 Sheets-Sheet 2.

JOHN C. WALSH EDWARD THOLLAND J/e. WILL/AM M HAZEL ro/v KENNE TH I? JUHLINVENTORS ATTORNEYS Patented Aug. 28, 1962 Free ARTICLE CARRIER FUROVERHEAD CONVEYOR John C. Walsh, William M. Haselton, Edward T. Holland,

Jr., and Kenneth P. .luhl, all of Cedar Rapids, Iowa,

assignors to Cherry-Burrell Corporation, Cedar Rapids,

Iowa, a corporation of Delaware Filed Apr. 25, 1960, Ser. No. 24,336 4Claims. (Cl. 104167) This invention relates to a conveyor hook structureand more particularly to an improved conveyor hook for translating therotary motion of a spiral drive shaft into linear motion thereby to movean article or load along a predetermined path.

In U.S. Patent No. 2,911,802 and in co-pending applications, Serial No.518,807, filed June 29, 1955, entitled Conveyor Structure, Serial No.666,023, filed June 17, 1957, now Patent No. 3,002,635, entitledConveyor and System, and Serial No. 16,610, filed March 21, 1960,entitled Conveyor Rail Structure and Method of Making the Same, allfiled in the name of Edward T. Holland, In, there are disclosed variousinventions relating to an overhead type conveyor utilizing a flexiblespiral driveshaft to translate rotary motion into linear motion. Asshown in these applications and in the patent, the hook upon which theload is suspended rides on a rail and is moved by engagement with thespiral winding on the drive-shaft either directly or through aprojecting nib. It is to this structure that our invention pertains.

As compared to the prior art, the conveyor hook disclosed herein iscapable of carrying increased loads while substantially eliminating wearon the conveyor rail itself. Also, our novel hook structure practicallyeliminates slippage on inclines, and if for any reason movement of theload should be hindered, there will be no damage to the conveyordrive-shaft. Our novel hook structure permits replacement of a part ofthe hook without replacement of the entire assembly as was heretoforenecessary. A further advantage of our invention is that, if desired, adriveshaft engaging member may be positioned on each side of thedepending portion of the hook, thereby permitting simple and rapidtransfer of the load from one portion of the conveyor system to theother.

It is therefore a principal object of our invention to provide aconveyor hook structure that is capable of carrying increased loads,particularly when traveling up an incline, on a conveyor of the spiraldrive-shaft type.

It is another object of our invention to provide a conveyor hookstructure that will substantially eliminate wear on the major componentsof the conveyor, namely, the top surfaces of the rail housing and thedrive-shaft itself.

It is a further object of our invention substantially to eliminate thepossibility of slippage particularly when the load is traveling up anincline. In other words, our invention substantially does away with thepossibility of the helical windings failing to engage the hook withsufficient force to propel it up an incline.

It is a still further object of our invention to eliminate thepossibility of damage to the main conveyor components if movement of theload or article being conveyed should become hindered or stopped whilethe drive-shaft continues rotating.

It is a still further object of our invention to provide a novel hookstructure utilizing a double shaft engaging member thereby facilitatingthe transfer of the load from one conveyor line to another.

It is a still further object of our invention to provide a hookstructure that is relatively easy to manufacture, inexpensive, and onethat when excessively worn does not require replacement of the entireassembly.

These and other objects of Our invention will be readily apparent from aconsideration of the following description taken in connection with theaccompanying drawings in which:

FIGURE 1 is a perspective View of a short section of a conveyor andshowing our novel hook structure;

FIGURE 2 is an end view of the drive-shaft engaging member of the hookstructure;

FIGURE 3 is a bottom view of the drive-shaft engaging member shown inFIGURE 2;

FIGURE 4 is a sectional View of the drive shaft engaging member taken onthe line 44 of FIGURE 3 and showing the shape of the teeth;

FIGURE 5 is a sectional view taken on the line 55 of FIGURE 1; and

FIGURE 6 is a perspective view of a portion of a conveyor systemillustrating the structure necessary to effect transfer from oneconveyor line to another.

Referring to FIGURE 1, the conveyor consists of a rail housing 10 and aspiral drive-shaft 12 rotatable in the housing 10. The drive-shaft 12 ismade up of a number of windings of wire that form a torsionally rigidbut laterally flexible core 14 (FIGURE 5). Wound on the exterior of thecore 14 is a helical winding 16 which we prefer to make of stainlesssteel. The details of the construction of this flexible spiraldrive'shaft are more fully set forth in US. application Serial No.518,807 referred to above. As best seen in FIGURE 5, the drive-shaft 12is preferably more than half surrounded by the C-shaped portion of thehousing 10 and the top of the shaft 12 is below the upper surfaces 18 ofthe rail housing 10.

The conveyor hook structure comprises a depending rod 20 to the bottomof which there is attached a pair of transverse rods 22 adapted to carrya package 23. Depending on the type of article or load to be carried,other suitable means can be substituted for the rods 22. The upper partof the rod 20 is bent over and secured to a cross bar 24. On each sideof the rod 20 and afiixed to the cross bar 24 there is a drive-shaftengaging member, indicated generally by the reference numeral 26, whichwe have termed for the sake of brevity a rack. The racks 26 arepreferably constructed of a plastic material, such as nylon, that hasgood wear resistance coupled with low friction and adequate strength.Racks 26 are each secured to the cross bar 24 by providing aninterference fit between the bar 24 and the opening to a circular groove28 formed in the top of rack 26 along its entire width. Since theplastic material nylon has a certain amount of resilience, the racks 26can be snapped onto the bar 24 and they will remain in place throughoutnormal use. The diameter of the groove 28 is itself slightly larger thanthe diameter of the bar 24 so that rack 26 can pivot freely on the bar24. To prevent the racks 26 from slipping oil? the ends of the bar 24, aflange 27 preferably is formed on each end of the bar 24. Also, aprojection 29 formed by pinching the bar 24 is provided on the top ofthe bar 24 to prevent the rack 26 from turning upside down on the bar 24and becoming out of position for rapid placement on the conveyor.

Referring now to FIGURES 2 and 3, the details of the rack 26 will bedescribed. On the lower side of the rack 26 there are formed twosurfaces 30. These two surfaces 30 extend parallel to one another andare spaced apart, one near each side of the rack 26. They are spaced adistance equal to the spacing of the top surfaces 18 of the rail housing10, thereby providing runners upon which the rack 26 can slide as it ismoved by action of the driveshaft 12. In the center of the rack 26 thereare five projections or teeth 32 formed at an angle that corresponds tothe helix angle of the winding 16 on the drive-shaft 12. Also, thespacing of the teeth 32 should correspond to the pitch of the winding 16and their depth must be sufficient to engage the winding 16 ofdrive-shaft 12 when the runners 30 are properly seated on the surfaces18 of rail housing 10.

We also prefer to make the teeth 32 tapered as it is difficult tomaintain a uniform pitch in the winding 16 because of its flexibility.If teeth 32 were made uniformly thick, they might jam between theconvolutions of winding 16 and cause breakage of the teeth 32. Thetapered teeth avoid this possibility by allowing rack 26 to ride up andposition itself without jamming. We have found that tooth breakage isthereby substantially eliminated.

To give the rack 26 added stability, We also prefer to provide on eachside thereof a flange or lip 34 which will overlap the sides of the railhousing 10. This will assure proper engagement of the teeth 32 withwinding 16 and tends to prevent the rack 26 from slipping off the railhousing 10.

Referring now to FIGURE 6, the purpose of providing side-by-side racks26 can be readily understood. The transfer assembly or switch shown inFIGURE 6 consists of two sections 36 and 38 of rail housing 10. Sections36 and 33 are held the proper distance from one another by a set ofbrackets 40 and 42 which also serve to support the assembly. Transferfrom one section 36 to the other section 38 is made very simply.

Note that the two sections 36 and 38 of the conveyor system firstconverge toward and then diverge from each other both in a horizontalplane and a vertical plane. Assume, for example, that a load beingcarried by a hook assembly is moving along conveyor 36, from right toleft in FIGURE 6, with one of the twin racks 26 riding on section 36while the other rack 26 extends outward. This load-carrying hookassembly is indicated in FIGURE 6 by the letter A. As the hook assemblyA moves from right to left, the rack 26 extending outward from thesection 36 will eventually reach a point where it will be placed on thesection 38. Then as the vassembly continues to travel from right toleft, it will remain on section 38 and be lifted off section 36 as thatsection curves downward. The position of load-carrying hook assemblyafter transfer to section 38 is illustrated in FIGURE 6 and identifiedby the letter B.

Thus, it is seen that the transfer from one conveyor section to anotheris easily made possible by the double rack design. The transfer assemblyrequires no special parts other than the brackets 40 and 42, theconveyor sections 36 and 38 being formed from the standard rail housing10.

It is thus seen that we have provided a simple and inexpensive transfermeans and also a greatly improved means of translating the rotary motionof the spiral drive-shaft 12 into linear movement of an article. Ournovel device also has superior wear qualities, and because it sustainsthe wear, wear on the rail housing 10 and drive-shaft 12 is practicallyeliminated without the necessity of lubrication.

Having thus described our invention, it will be apparent to thoseskilled in the art that various modifications may be made withoutdeparting from the spirit and scope of the invention. It is ourintention that any such revisions or variations of the invention as arereasonably expected on the part of those skilled in the art will beincluded within the scope of the following claims.

We claim:

1. Fo use with an overhead conveyor having a spiral drive shaftrotatable in a housing that provides load supporting surfaces, anarticle carrier comprising a pair of runners laterally spaced apart anamount to engage said surfaces slidingly, a plurality of projectionsbetween said runners adapted to engage said drive shaft, and a flangeextending downwardly outside each of said runners to engage the exteriorof said housing, said runners, projections and flanges forming aone-piece shaft engaging member, said member being formed of a lowfriction, wear resistant material.

2. For use with an overhead conveyor having a spiral drive shaftrotatable in a housing that provides load supporting surfaces, anarticle carrier comprising a pair of runners laterally spaced apart anamount to engage said surfaces slidingly, a plurality of projectionsbetween said runners adapted to engage said drive shaft, said runnersand said projections forming a one-piece member, said member beingformed of a low friction, wear resistant material and having on the sideopposite said projections a circular shaped groove extending laterallyacross the length of said member, and a round bar pivotally seated insaid groove, said bar having connected thereto means for supporting thearticle to be conveyed.

3. The article carrier of claim 1 in which said projections aresubstantially rectangular in cross-section and tapered.

4. The article carrier of claim 3 in which said projections are at anangle with said runners, the angle corresponding to the pitch of saidspiral drive shaft.

References Cited in the file of this patent UNITED STATES PATENTS1,774,360 Dreng witz Aug. 26, 1930 2,681,015 Davis June 15, 19542,726,077 Dow Dec. 6, 1955 2,908,379 Hamilton Oct. 13, 1959

